1. Field of the Invention
The present invention relates to a dust control system for a power tool having a rotatable element for sawing or grinding.
2. Description of the Prior Art
In any sawing or grinding operation employing a disk-shaped or circular rotary saw blade or rotatable grinding element a considerable quantity of dust is produced as the rotatable element cuts or grinds through the material being sawed or ground. The volume and nature of dust produced presents a particular problem in sawing stone, concrete or mortar.
At one time the dust generated from sawing concrete with a rotary saw was controlled by directing a flow of water to the saw blade so as to both cool the saw blade and carry away particulates of concrete or mortar dust generated as the saw cut through concrete or mortar. This necessitated a supply of water to the location at which the concrete or mortar was to be cut. In some locations it is extremely difficult to provide a cooling water supply to a rotary saw used for cutting concrete or mortar. For example, mortar is often cut from between bricks on the side of a building in preparation for tuck pointing the bricks where the mortar has begun to crack and loosen. On tall buildings especially it is extremely difficult to provide a cooling water supply to a concrete saw being used to saw out cracked mortar from between bricks.
In recent years the cutting of mortar and concrete has been performed with power saws employing blades containing diamond cutting elements. Such implements are very advantageous since no cooling water supply is required where diamond tip rotary blades are utilized. However, one major disadvantage of the elimination of cooling water is the large amount of very fine dust generated during the sawing operation. The immediate environment of an individual operating the saw is filled with this very fine dust. The operator must therefore wear a mask to attempt to keep the dust out of his nose, mouth and lungs. Such masks are only partially effective, however. Furthermore, the clouds of dust generated reduce the operator's visibility, thereby slowing the pace at which the concrete can be cut.